On Expressed Yeast-cell Plasma (Buclmer's " Zymase "). 253 



enzyme was of a very active character, and produced a rapid digestion 

 of the proteid constituents of the juice. 



It occasionally happens that great reluctance is displayed by the 

 juice in leaving the kieselguhr sponge when under pressure. This 

 has most frequently happened with very new yeasts that is, yeast 

 skimmed from the fermentation vats and used directly for the pre- 

 paration of the juice. There is some evidence to lead us to suppose 

 that this difficulty is correlated with a similar difficulty which is met 

 with when attempting to prepare as near the living condition as 

 possible an intracellular juice of an organ or tissue. For instance, a 

 liver removed from a dog at the moment of death and at once disin- 

 tegrated will yield no juice on pressing, even if the pressure be raised 

 to a thousand atmospheres or more ; whereas a liver not so fresh will 

 yield its juice without difficulty. That kieselguhr has the power of 

 arresting the passage of certain albuminous bodies can easily be 

 demonstrated. Thus we have found that egg globulins are almost 

 entirely retained in a kieselguhr sponge, and even albumin and serum 

 proteids are retained to a certain extent. It therefore is suggested 

 that the juice that was used in the following work was in every case 

 far removed in nature from the condition in which it existed when 

 alive within the yeast-cell ; but on the other hand it is much nearer 

 the living condition than that obtained by Buchner, owing to the fact 

 that he employed water to extract his juice, and water as will be 

 shown has a decided action on the juices we obtained. 



We are therefore placed in the difficult position that those condi- 

 tions in which the juice is nearest its living condition are just those 

 when it cannot be obtained by the convenient method of pressing. 

 Under such circumstances resort must be had to centrif ugalising ; but 

 the process is tedious in the extreme, and by the time it is completed 

 in all probability the juice has altered in composition. We hope soon 

 to be in a position to overcome this difficulty. 



Properties of the Cell Plasma. In the course of our experiments we 

 employed yeast from five different breweries, which we will designate 

 as A, B, C, D, and E. The first three (A, B, and C) were breweries in 

 the London district, D was in the south of England, and E was one of 

 the very few bottom-fermentation breweries in this country. The 

 greater number of our experiments were made with yeasts from A 

 and B, the yeasts from C, D, and E being only used in one or two 

 instances. 



From the outset we found that in practically all cases the juice 

 obtained from the yeasts freely evolved gas, both when standing alone 

 and with the addition of sugar. Our results in the latter respect were 

 fully equal to, and in some instances surpassed, those of Buchner. 



We were, however, early confronted with the fact that the auto- or self- 

 fermentation of the juice gave rise to a considerable volume of gas, a 



